nfs4file.c

  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 *  linux/fs/nfs/file.c
  4 *
  5 *  Copyright (C) 1992  Rick Sladkey
  6 */
  7#include <linux/fs.h>
  8#include <linux/file.h>
  9#include <linux/falloc.h>
 10#include <linux/mount.h>
 11#include <linux/nfs_fs.h>
 12#include <linux/nfs_ssc.h>
 13#include <linux/splice.h>
 14#include "delegation.h"
 15#include "internal.h"
 16#include "iostat.h"
 17#include "fscache.h"
 18#include "pnfs.h"
 19
 20#include "nfstrace.h"
 21
 22#ifdef CONFIG_NFS_V4_2
 23#include "nfs42.h"
 24#endif
 25
 26#define NFSDBG_FACILITY		NFSDBG_FILE
 27
 28static int
 29nfs4_file_open(struct inode *inode, struct file *filp)
 30{
 31	struct nfs_open_context *ctx;
 32	struct dentry *dentry = file_dentry(filp);
 33	struct dentry *parent = NULL;
 34	struct inode *dir;
 35	unsigned openflags = filp->f_flags;
 36	struct iattr attr;
 37	int err;
 38
 39	/*
 40	 * If no cached dentry exists or if it's negative, NFSv4 handled the
 41	 * opens in ->lookup() or ->create().
 42	 *
 43	 * We only get this far for a cached positive dentry.  We skipped
 44	 * revalidation, so handle it here by dropping the dentry and returning
 45	 * -EOPENSTALE.  The VFS will retry the lookup/create/open.
 46	 */
 47
 48	dprintk("NFS: open file(%pd2)\n", dentry);
 49
 50	err = nfs_check_flags(openflags);
 51	if (err)
 52		return err;
 53
 54	/* We can't create new files here */
 55	openflags &= ~(O_CREAT|O_EXCL);
 56
 57	parent = dget_parent(dentry);
 58	dir = d_inode(parent);
 59
 60	ctx = alloc_nfs_open_context(file_dentry(filp),
 61				     flags_to_mode(openflags), filp);
 62	err = PTR_ERR(ctx);
 63	if (IS_ERR(ctx))
 64		goto out;
 65
 66	attr.ia_valid = ATTR_OPEN;
 67	if (openflags & O_TRUNC) {
 68		attr.ia_valid |= ATTR_SIZE;
 69		attr.ia_size = 0;
 70		filemap_write_and_wait(inode->i_mapping);
 71	}
 72
 73	inode = NFS_PROTO(dir)->open_context(dir, ctx, openflags, &attr, NULL);
 74	if (IS_ERR(inode)) {
 75		err = PTR_ERR(inode);
 76		switch (err) {
 77		default:
 78			goto out_put_ctx;
 79		case -ENOENT:
 80		case -ESTALE:
 81		case -EISDIR:
 82		case -ENOTDIR:
 83		case -ELOOP:
 84			goto out_drop;
 85		}
 86	}
 87	if (inode != d_inode(dentry))
 88		goto out_drop;
 89
 90	nfs_file_set_open_context(filp, ctx);
 91	nfs_fscache_open_file(inode, filp);
 92	err = 0;
 93	filp->f_mode |= FMODE_CAN_ODIRECT;
 94
 95out_put_ctx:
 96	put_nfs_open_context(ctx);
 97out:
 98	dput(parent);
 99	return err;
100
101out_drop:
102	d_drop(dentry);
103	err = -EOPENSTALE;
104	goto out_put_ctx;
105}
106
107/*
108 * Flush all dirty pages, and check for write errors.
109 */
110static int
111nfs4_file_flush(struct file *file, fl_owner_t id)
112{
113	struct inode	*inode = file_inode(file);
114	errseq_t since;
115
116	dprintk("NFS: flush(%pD2)\n", file);
117
118	nfs_inc_stats(inode, NFSIOS_VFSFLUSH);
119	if ((file->f_mode & FMODE_WRITE) == 0)
120		return 0;
121
122	/*
123	 * If we're holding a write delegation, then check if we're required
124	 * to flush the i/o on close. If not, then just start the i/o now.
125	 */
126	if (!nfs4_delegation_flush_on_close(inode))
127		return filemap_fdatawrite(file->f_mapping);
128
129	/* Flush writes to the server and return any errors */
130	since = filemap_sample_wb_err(file->f_mapping);
131	nfs_wb_all(inode);
132	return filemap_check_wb_err(file->f_mapping, since);
133}
134
135#ifdef CONFIG_NFS_V4_2
136static ssize_t __nfs4_copy_file_range(struct file *file_in, loff_t pos_in,
137				      struct file *file_out, loff_t pos_out,
138				      size_t count, unsigned int flags)
139{
140	struct nfs42_copy_notify_res *cn_resp = NULL;
141	struct nl4_server *nss = NULL;
142	nfs4_stateid *cnrs = NULL;
143	ssize_t ret;
144	bool sync = false;
145
146	/* Only offload copy if superblock is the same */
147	if (file_in->f_op != &nfs4_file_operations)
148		return -EXDEV;
149	if (!nfs_server_capable(file_inode(file_out), NFS_CAP_COPY) ||
150	    !nfs_server_capable(file_inode(file_in), NFS_CAP_COPY))
151		return -EOPNOTSUPP;
152	if (file_inode(file_in) == file_inode(file_out))
153		return -EOPNOTSUPP;
154	/* if the copy size if smaller than 2 RPC payloads, make it
155	 * synchronous
156	 */
157	if (count <= 2 * NFS_SERVER(file_inode(file_in))->rsize)
158		sync = true;
159retry:
160	if (!nfs42_files_from_same_server(file_in, file_out)) {
161		/*
162		 * for inter copy, if copy size is too small
163		 * then fallback to generic copy.
164		 */
165		if (sync)
166			return -EOPNOTSUPP;
167		cn_resp = kzalloc(sizeof(struct nfs42_copy_notify_res),
168				  GFP_KERNEL);
169		if (unlikely(cn_resp == NULL))
170			return -ENOMEM;
171
172		ret = nfs42_proc_copy_notify(file_in, file_out, cn_resp);
173		if (ret) {
174			ret = -EOPNOTSUPP;
175			goto out;
176		}
177		nss = &cn_resp->cnr_src;
178		cnrs = &cn_resp->cnr_stateid;
179	}
180	ret = nfs42_proc_copy(file_in, pos_in, file_out, pos_out, count,
181				nss, cnrs, sync);
182out:
183	kfree(cn_resp);
184
185	if (ret == -EAGAIN)
186		goto retry;
187	return ret;
188}
189
190static ssize_t nfs4_copy_file_range(struct file *file_in, loff_t pos_in,
191				    struct file *file_out, loff_t pos_out,
192				    size_t count, unsigned int flags)
193{
194	ssize_t ret;
195
196	ret = __nfs4_copy_file_range(file_in, pos_in, file_out, pos_out, count,
197				     flags);
198	if (ret == -EOPNOTSUPP || ret == -EXDEV)
199		ret = splice_copy_file_range(file_in, pos_in, file_out,
200					     pos_out, count);
201	return ret;
202}
203
204static loff_t nfs4_file_llseek(struct file *filep, loff_t offset, int whence)
205{
206	loff_t ret;
207
208	switch (whence) {
209	case SEEK_HOLE:
210	case SEEK_DATA:
211		ret = nfs42_proc_llseek(filep, offset, whence);
212		if (ret != -EOPNOTSUPP)
213			return ret;
214		fallthrough;
215	default:
216		return nfs_file_llseek(filep, offset, whence);
217	}
218}
219
220static long nfs42_fallocate(struct file *filep, int mode, loff_t offset, loff_t len)
221{
222	struct inode *inode = file_inode(filep);
223	long ret;
224
225	if (!S_ISREG(inode->i_mode))
226		return -EOPNOTSUPP;
227
228	switch (mode) {
229	case 0:
230	case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE:
231	case FALLOC_FL_ZERO_RANGE:
232		break;
233	default:
234		return -EOPNOTSUPP;
235	}
236
237	ret = inode_newsize_ok(inode, offset + len);
238	if (ret < 0)
239		return ret;
240
241	if (mode & FALLOC_FL_PUNCH_HOLE)
242		return nfs42_proc_deallocate(filep, offset, len);
243	else if (mode & FALLOC_FL_ZERO_RANGE)
244		return nfs42_proc_zero_range(filep, offset ,len);
245	return nfs42_proc_allocate(filep, offset, len);
246}
247
248static loff_t nfs42_remap_file_range(struct file *src_file, loff_t src_off,
249		struct file *dst_file, loff_t dst_off, loff_t count,
250		unsigned int remap_flags)
251{
252	struct inode *dst_inode = file_inode(dst_file);
253	struct nfs_server *server = NFS_SERVER(dst_inode);
254	struct inode *src_inode = file_inode(src_file);
255	unsigned int bs = server->clone_blksize;
256	int ret;
257
258	/* NFS does not support deduplication. */
259	if (remap_flags & REMAP_FILE_DEDUP)
260		return -EOPNOTSUPP;
261
262	if (remap_flags & ~REMAP_FILE_ADVISORY)
263		return -EINVAL;
264
265	if (IS_SWAPFILE(dst_inode) || IS_SWAPFILE(src_inode))
266		return -ETXTBSY;
267
268	/* check alignment w.r.t. clone_blksize */
269	ret = -EINVAL;
270	if (bs) {
271		if (!IS_ALIGNED(src_off, bs) || !IS_ALIGNED(dst_off, bs))
272			goto out;
273		if (!IS_ALIGNED(count, bs) && i_size_read(src_inode) != (src_off + count))
274			goto out;
275	}
276
277	/* XXX: do we lock at all? what if server needs CB_RECALL_LAYOUT? */
278	lock_two_nondirectories(src_inode, dst_inode);
279	/* flush all pending writes on both src and dst so that server
280	 * has the latest data */
281	nfs_file_block_o_direct(NFS_I(src_inode));
282	ret = nfs_sync_inode(src_inode);
283	if (ret)
284		goto out_unlock;
285	nfs_file_block_o_direct(NFS_I(dst_inode));
286	ret = nfs_sync_inode(dst_inode);
287	if (ret)
288		goto out_unlock;
289
290	ret = nfs42_proc_clone(src_file, dst_file, src_off, dst_off, count);
291
292	/* truncate inode page cache of the dst range so that future reads can fetch
293	 * new data from server */
294	if (!ret)
295		truncate_inode_pages_range(&dst_inode->i_data, dst_off, dst_off + count - 1);
296
297out_unlock:
298	unlock_two_nondirectories(src_inode, dst_inode);
299out:
300	return ret < 0 ? ret : count;
301}
302
303static int read_name_gen = 1;
304#define SSC_READ_NAME_BODY "ssc_read_%d"
305
306static struct file *__nfs42_ssc_open(struct vfsmount *ss_mnt,
307		struct nfs_fh *src_fh, nfs4_stateid *stateid)
308{
309	struct nfs_fattr *fattr = nfs_alloc_fattr();
310	struct file *filep, *res;
311	struct nfs_server *server;
312	struct inode *r_ino = NULL;
313	struct nfs_open_context *ctx;
314	struct nfs4_state_owner *sp;
315	char *read_name = NULL;
316	int len, status = 0;
317
318	server = NFS_SB(ss_mnt->mnt_sb);
319
320	if (!fattr)
321		return ERR_PTR(-ENOMEM);
322
323	status = nfs4_proc_getattr(server, src_fh, fattr, NULL);
324	if (status < 0) {
325		res = ERR_PTR(status);
326		goto out;
327	}
328
329	if (!S_ISREG(fattr->mode)) {
330		res = ERR_PTR(-EBADF);
331		goto out;
332	}
333
334	res = ERR_PTR(-ENOMEM);
335	len = strlen(SSC_READ_NAME_BODY) + 16;
336	read_name = kzalloc(len, GFP_KERNEL);
337	if (read_name == NULL)
338		goto out;
339	snprintf(read_name, len, SSC_READ_NAME_BODY, read_name_gen++);
340
341	r_ino = nfs_fhget(ss_mnt->mnt_sb, src_fh, fattr);
342	if (IS_ERR(r_ino)) {
343		res = ERR_CAST(r_ino);
344		goto out_free_name;
345	}
346
347	filep = alloc_file_pseudo(r_ino, ss_mnt, read_name, O_RDONLY,
348				     r_ino->i_fop);
349	if (IS_ERR(filep)) {
350		res = ERR_CAST(filep);
351		iput(r_ino);
352		goto out_free_name;
353	}
354
355	ctx = alloc_nfs_open_context(filep->f_path.dentry,
356				     flags_to_mode(filep->f_flags), filep);
357	if (IS_ERR(ctx)) {
358		res = ERR_CAST(ctx);
359		goto out_filep;
360	}
361
362	res = ERR_PTR(-EINVAL);
363	sp = nfs4_get_state_owner(server, ctx->cred, GFP_KERNEL);
364	if (sp == NULL)
365		goto out_ctx;
366
367	ctx->state = nfs4_get_open_state(r_ino, sp);
368	if (ctx->state == NULL)
369		goto out_stateowner;
370
371	set_bit(NFS_SRV_SSC_COPY_STATE, &ctx->state->flags);
372	memcpy(&ctx->state->open_stateid.other, &stateid->other,
373	       NFS4_STATEID_OTHER_SIZE);
374	update_open_stateid(ctx->state, stateid, NULL, filep->f_mode);
375	set_bit(NFS_OPEN_STATE, &ctx->state->flags);
376
377	nfs_file_set_open_context(filep, ctx);
378	put_nfs_open_context(ctx);
379
380	file_ra_state_init(&filep->f_ra, filep->f_mapping->host->i_mapping);
381	res = filep;
382out_free_name:
383	kfree(read_name);
384out:
385	nfs_free_fattr(fattr);
386	return res;
387out_stateowner:
388	nfs4_put_state_owner(sp);
389out_ctx:
390	put_nfs_open_context(ctx);
391out_filep:
392	fput(filep);
393	goto out_free_name;
394}
395
396static void __nfs42_ssc_close(struct file *filep)
397{
398	struct nfs_open_context *ctx = nfs_file_open_context(filep);
399
400	ctx->state->flags = 0;
401}
402
403static const struct nfs4_ssc_client_ops nfs4_ssc_clnt_ops_tbl = {
404	.sco_open = __nfs42_ssc_open,
405	.sco_close = __nfs42_ssc_close,
406};
407
408/**
409 * nfs42_ssc_register_ops - Wrapper to register NFS_V4 ops in nfs_common
410 *
411 * Return values:
412 *   None
413 */
414void nfs42_ssc_register_ops(void)
415{
416	nfs42_ssc_register(&nfs4_ssc_clnt_ops_tbl);
417}
418
419/**
420 * nfs42_ssc_unregister_ops - wrapper to un-register NFS_V4 ops in nfs_common
421 *
422 * Return values:
423 *   None.
424 */
425void nfs42_ssc_unregister_ops(void)
426{
427	nfs42_ssc_unregister(&nfs4_ssc_clnt_ops_tbl);
428}
429#endif /* CONFIG_NFS_V4_2 */
430
431static int nfs4_setlease(struct file *file, int arg, struct file_lease **lease,
432			 void **priv)
433{
434	return nfs4_proc_setlease(file, arg, lease, priv);
435}
436
437const struct file_operations nfs4_file_operations = {
438	.read_iter	= nfs_file_read,
439	.write_iter	= nfs_file_write,
440	.mmap_prepare	= nfs_file_mmap_prepare,
441	.open		= nfs4_file_open,
442	.flush		= nfs4_file_flush,
443	.release	= nfs_file_release,
444	.fsync		= nfs_file_fsync,
445	.lock		= nfs_lock,
446	.flock		= nfs_flock,
447	.splice_read	= nfs_file_splice_read,
448	.splice_write	= iter_file_splice_write,
449	.check_flags	= nfs_check_flags,
450	.setlease	= nfs4_setlease,
451#ifdef CONFIG_NFS_V4_2
452	.copy_file_range = nfs4_copy_file_range,
453	.llseek		= nfs4_file_llseek,
454	.fallocate	= nfs42_fallocate,
455	.remap_file_range = nfs42_remap_file_range,
456#else
457	.llseek		= nfs_file_llseek,
458#endif
459	.fop_flags	= FOP_DONTCACHE,
460};